Abstract: In a system for monitoring an output of a sensor for detecting an operating state of a gas turbine engine by comparing a value of an output of the sensor with a prescribed reference value, a calibration map for converting the output of the sensor into a variable that is normally used for controlling the engine is used for defining the reference value for determining the state of the sensor. Thereby, a fault of a sensor can be detected both accurately and promptly by using the existing resource without unduly complicating the control program. It is particularly desirable to monitor the output of the sensor by taking into account the current operating condition of the engine to improve the reliability in detecting a fault in the sensor.

Abstract: An energy-saving driving promotion system includes: a vehicle state detecting device; a current value calculating device that calculates a current value associated with an accelerator operation amount or a vehicle drive power; a recommended value calculating device that calculates a recommended value associated with the accelerator operation amount or the vehicle drive power; an indicator device that indicates a relationship between the calculated recommended value and the calculated current value; and an acceleration intention determining device that determines whether a driver intends to accelerate. If the acceleration intention determining device determines that the driver intends to accelerate, the recommended value calculating device calculates a larger recommended value when the acceleration intention determining device determines that the driver intends to accelerate than when the acceleration intention determining device determines that the driver does not intend to accelerate.

Abstract: The stimulation of waves in bars, in particular at high amplitudes, is used for the calibration of acceleration and force sensors. The invention relates to a method and a device for calibrating acceleration and force sensors by means of a Hopkinson bar for controlled influencing of the signal form the signal amplitude and the pulse duration of the signals over a large amplitude range. A reference sensor and the sensor for calibration are arranged on the Hopkinson bar. At the end of the Hopkinson bar opposite the sensors the stimulation is carried out by means of an electromechanical actuator for converting an electrical signal into a mechanical force. The electromechanical actuator may be controlled by a control and regulation electronic circuit. A targeted influence and change in the acceleration and force pulse form can be achieved.

Abstract: Methods are provided for calibrating a tachometer or generator device to reduce residual errors associated with the tachometer-generator device. A shim structure is positioned within the air gap of the tachometer-generator device. A physical characteristic or location of placement of the shim structure is selected to reduce variation in an output voltage of the tachometer-generator device.

Abstract: A method for re-calibrating an anemometer of a wind turbine is provided, the method comprising the steps of obtaining pairs of measured values of wind speed and a wind-speed dependent turbine variable; comparing said measured value pairs to pairs of wind speed and the turbine variable obtained from an expected turbine variable curve of the wind turbine to determine a difference between a measured wind speed value and an expected wind speed value for a given turbine variable value; and adjusting a calibration function of said anemometer on the basis of said determined difference.

Abstract: A mobile navigation system gyro module comprises: first and second gyro sensors outputting angular velocities ?1, ?2 around first and second axes intersecting at an acute angle ?12; a sign determination circuit determining a sign of ?1; a correction circuit correcting the first and second gyro sensor outputs; and a computation circuit computing ??=?(?1?2+SA2) and SA=(?2???1? cos ?12)/sin ?12 using angular velocities ?1?, ?2? from the correction circuit, and outputting angular velocity ? by multiplying ?? by the sign of ?1, wherein the correction circuit includes: first and second offset adjustment circuits outputting ?1? and ?2? by respectively subtracting from ?1 and ?2, corrections B1 and B2 corresponding to the first and second gyro sensor outputs when the mobile unit stops; and the angular velocity ? is around an axis coplanar with and between the first and second axes.

Abstract: A traveling direction measuring apparatus including 3-axes acceleration detecting means for detecting acceleration, and acceleration data acquiring means for repeatedly obtaining 3-axes acceleration data, said 3-axes acceleration varying with walking of a pedestrian, the traveling direction measuring apparatus including means for calculating, when the pedestrian is walking with holding said traveling direction measuring apparatus in a generally fixed attitude, gravity acceleration by averaging acceleration data sets during several steps obtained by said acceleration data acquiring means, means for calculating frequency components corresponding to duration of one step of the acceleration data sets projected on a plane perpendicular to the calculated gravity acceleration, and means for estimating a moving direction of the pedestrian seen from a terminal coordinate system associated with said traveling direction measuring apparatus according to frequency components.

Abstract: Some embodiments of the present invention provide a system that generates a simulated vibration pattern in a computer subsystem. During operation, a vibration pattern is monitored at a location in the computer subsystem, wherein the vibration pattern is monitored while the computer subsystem is incorporated into the computer system and the computer system is operating. Then, the vibrations of the computer subsystem are mimicked by generating the simulated vibration pattern at the same location in the computer subsystem based on the monitored vibration pattern.

Abstract: The method and apparatus in one embodiment may have: operating one of two resonators of a class II coriolis vibratory gyro in a closed loop mode and another of the two resonators in an open loop whole angle mode; sensing an angular rate by each of the two resonators; calibrating the scale factor of the closed loop resonator to yield the same integrated whole angle as measured by the open loop resonator; reversing operation of the two resonators such that the one of two resonators is operated in an open loop mode and the another of the two resonators in a closed loop whole angle mode; and alternately proceeding between open and closed loop operation of the two resonators, thereby self-calibrating scale factors respectively of the two resonators.

Abstract: The method and apparatus in one embodiment may have: operating one of two resonators of a class II coriolis vibratory gyro in a closed loop mode and another of the two resonators in an open loop whole angle mode; sensing an angular rate by each of the two resonators; calibrating the scale factor of the closed loop resonator to yield the same integrated whole angle as measured by the open loop resonator; reversing operation of the two resonators such that the one of two resonators is operated in an open loop mode and the another of the two resonators in a closed loop whole angle mode; and alternately proceeding between open and closed loop operation of the two resonators, thereby self-calibrating scale factors respectively of the two resonators.

Abstract: A wheel-speed-sensor-anomaly detection apparatus detects anomaly of wheel speed sensors of a vehicle. When a difference between the minimum wheel speed among detected wheel speeds and the smallest value among the remaining wheel speeds is greater than a predetermined threshold value, in principle, a wheel speed sensor of the wheel corresponding to the minimum wheel speed is determined to be anomalous. Meanwhile, when a wheel having a lowered tire air pressure (air-pressure-lowered wheel) is present and a road surface on which the vehicle is currently traveling is a low-? road surface, the operation of detecting anomaly of the wheel speed sensors is prohibited. This operation reliably prevents erroneous detection of anomaly of the wheel speed sensor of the air-pressure-lowered wheel, which erroneous detection would otherwise occur due to the locking tendency of the air-pressure-lowered wheel occurring because of decreased tire air pressure, in particular, on a low-? road surface.

Abstract: A sensor with continuous self test (101). An exemplary inertial sensor (106) may include one or more self test electrodes (208, 210) so that one or more test signals (402, 404) may be applied to the electrodes (208, 210) during normal operation of the sensor. Normal sensor output may be read and stored (316) during normal operation, when self test signals are typically not applied to the sensor. The normal sensor output provides a baseline for comparison to a sensor offset error detection signal (408) produced when a test signal may be applied to one self test electrode, and also to a sense error detection signal (406) produced when a test signal may be applied to both self test electrodes (208, 210).

Abstract: The invention concerns a sensor with silicon-containing components from whose sensitive detection element electrical signals relevant to a present analyte can be read out by means of a silicon semiconductor system. The invention is characterized in that the silicon-containing components are covered with a layer made of hydrophobic material in order to prevent unwanted signals caused by moisture.

Abstract: The present invention relates to a method for adjusting the resonant frequencies of a vibrating microelectromechanical (MEMS) device. In one embodiment, the present invention is a method for adjusting the resonant frequencies of a vibrating mass including the steps of patterning a surface of a device layer of the vibrating mass with a mask, etching the vibrating mass to define a structure of the vibrating mass, determining a first set of resonant frequencies of the vibrating mass, determining a mass removal amount of the vibrating mass and a mass removal location of the vibrating mass to obtain a second set of resonant frequencies of the vibrating mass, removing the mask at the mass removal location, and etching the vibrating mass to remove the mass removal amount of the vibrating mass at the mass removal location of the vibrating mass.

Abstract: An angular velocity sensor unit judging whether there is a failure in both of two angular velocity sensors. The angular velocity sensor unit includes a first angular velocity sensor (12) and a second angular velocity sensor (13), each including an oscillator having a shaft portion and an oscillatory portion. Each of the angular velocity sensors (12, 13) is arranged such that its shaft portion is not in parallel with an XY-plane defined by an X-axis and a Y-axis of three orthogonal axes. The failure of the second angular velocity sensor is judged based on whether or not a detection value of an angular velocity about a Z-axis lies outside a tolerance range of a detection value of the angular velocity about the Z-axis by the other angular velocity sensor, and the failure of the first angular velocity sensor is judged by comparison with a pseudo-calculated angular velocity.

Abstract: A vehicle velocity detector 15 is provided, velocity V is detected from position data of the vehicle calculated by using signal from satellites, which is received by a GPS receiver 11 installed to a vehicle body, wheel rotation velocity Vw0 detected by a wheel velocity sensor 12 is corrected in accordance with tire inner pressure detected by a pressure sensor 13 so as to obtain wheel rotation velocity (correction value) Vw, velocity ratio R=(Vw/V), which is ratio of the corrected wheel rotation velocity Vw and the detected wheel velocity V, is calculated and tire wear amount is estimated in accordance with velocity ratio R so that tire wear amount can be measured precisely without processing the tire tread portion.

Abstract: An angular velocity detection circuit is connected to a resonator for making excited vibration on the basis of a drive signal and detects an angular velocity. The angular velocity detection circuit includes: a self-vibration component extraction unit that receives, from the resonator, a detection signal including an angular velocity component based on a Coriolis force and a self-vibration component based on the excited vibration and extracts the self-vibration component from the detection signal; a direct-current conversion unit including an integration unit that integrates an output signal of the self-vibration component extraction unit; and a temperature characteristic compensation unit that compensates for a variation due to a temperature in an output signal of the direct-current conversion unit.

Abstract: A micro-electro-mechanical gyroscope includes a first mass, which is able to oscillate along a first axis with respect to a fixed body, an inertial sensor having a second mass constrained to the first mass so as to oscillate along a second axis in response to a rotation of the gyroscope, a driving device coupled to the first mass that forms a control loop for maintaining the first mass in oscillation at a resonance frequency, and a reading device that detects displacements of the second mass along the second axis, which includes a charge amplifier for converting charge packets supplied by the inertial sensor into a charge-integration signal, and a low-pass filter. A calibration stage enables modification of a voltage between the second mass and the fixed body so as to minimize a component at a frequency that is twice the resonance frequency in the charge-integration signal.

Abstract: A closed loop scale factor estimator of an apparatus in one example is configured to compare a measured flex angle of a hemispherical resonator gyroscope (HRG) with a demodulation angle signal to estimate a force-to-rebalance (FTR) scale factor for the HRG, wherein the demodulation angle signal corresponds to an integral of a non-uniform rate signal applied to the HRG.

Abstract: A periodic test signal (44) is injected into a sensor and the sensor output (46) is compared to a threshold to determined whether the sensor is functioning properly.

Abstract: A system, computer program product and method of obtaining a performance parameter associated with a sensor, such as an accelerometer, is provided. The method includes applying an acceleration to the accelerometer and a first frequency to obtain a sensitivity of the accelerometer at the first frequency. A first self-test is performed on the accelerometer. The first self-test includes stimulating the accelerometer with a first self-test stimulation signal encoded with the first frequency, such that the accelerometer outputs a first signal. A self-test equivalent acceleration is then determined based, at least in part, on the first signal and the accelerometer sensitivity at the first frequency. A second self-test is performed on the accelerometer. The second self-test includes stimulating the accelerometer with a second self-test stimulation signal encoded with the second frequency, such that the accelerometer outputs a second signal.

Abstract: A vibrating gyroscope comprising: a proof mass (1); a spring suspension system (5, 6, 7, 8; 9) for suspending the proof mass; an electrical drive mechanism for vibrating the proof mass along a drive axis (x); electrodes (2, 3) for building together with at least a part of the proof mass (1) a capacitance system for detecting moves of the proof mass along a sense axis (z) perpendicular to the drive axis. The gyroscope is arranged so that quadrature forces generate displacements of the proof mass without substantially displacing the neutral point (10) of the proof mass along the sense axis (z). This may be achieved by tilting the proof mass while keeping its neutral point at a constant position along the sense axis, or by applying a constant electrostatic force.

Abstract: A method for evaluating and/or compensating the acceleration offset in a combined accelerometer and gyroscope, wherein the evaluation or compensation is based on a quadrature signal delivered by the accelerometer.

Abstract: A method for calibrating a multiple-triad triaxial accelerometer is provided. The method may include receiving accelerometer measured output from a first measurement triad and at least one additional measurement triad of the accelerometer. The method may further include aligning the output of a x, y, and z components of the first measurement triad to be substantially orthogonal with respect to each other, aligning the output of x, y, and z components of at least one additional measurement triad to be substantially orthogonal with respect to each other, and rotating the output of at least one measurement triad so the outputs of all measurement triads substantially align with each other. The method may further include storing the result of the alignment and rotation associated with at least one calibration function associated with the multiple-triad triaxial accelerometer. The alignment and rotation may be performed substantially simultaneously.

Abstract: A method and apparatus for calibrating wheel speed signals measured by wheel rpm sensors in a vehicle equipped with at least one longitudinal acceleration sensor integrates the signal of the longitudinal acceleration sensor during the acceleration or deceleration phases of the vehicle, and the resulting vehicle speed signal is compared against the signals of the individual wheel rpm sensors. A determination is made as to whether a deviation that may exist for a wheel lies within a predefined tolerance range. If a deviation falls outside of the tolerance range, the parameterized tire circumference of the associated wheel is adaptively recalibrated until the deviation falls within the tolerance range.

Abstract: Provided is an apparatus for measuring acceleration and a tilt angle using thermal convection of a fluid which includes a container containing the fluid, a heating body including a first heating element and a second heating element arranged in the container and a crosspoint that is formed as end portions of the first and second heating elements are electrically connected, and radiating heat when current is applied through the other end portions of the first and second heating elements, and a thermocouple including a thermocouple junction that contacts the crosspoint of the heating body and being point-symmetric with the heating body with respect to the crosspoint of the heating body, wherein a voltage between both end portions of the thermocouple is measured to calculate a temperature of the crosspoint of the heating body.

Abstract: The apparatus in one embodiment may have capacitive bulk acoustic wave disk gyro operated in a closed loop mode. A self-calibration system may be operatively coupled to the capacitive bulk acoustic wave disk gyroscope. Self-calibration of gyro bias of the gyro may be implemented by interchanging an anti-nodal axis with a nodal axis of the gyro.

Abstract: A method of verifying the operation of an accelerometer is provided. The method includes channeling a high frequency signal through a positive lead of the accelerometer, and detecting a signal at a negative lead of the accelerometer. If the detected signal is substantially similar to the high frequency signal channeled through the positive lead, the integrity of the accelerometer is verified.

Abstract: A method of correcting accelerometer and magnetometer measurements made in a well, comprising: making a series of triaxial measurements with magnetometers and accelerometers in an interval of the well to derive measured values of gravitational acceleration g, magnetic filed intensity B and the sine of the magnetic inclination sinl; obtaining known values of g, B and sinl for the interval; determining values of a correction to be applied to the measured values by simultaneously minimising the difference between the measured values and the known values of g, B and sinl for the interval; and applying the correction to the measured values to obtain in situ corrected values for g, B and sinl.

Abstract: Apparatus, methods, and systems for incorporating and reading a plurality of bridge sensors is disclosed. The bridge sensors may be capacitive bridge sensors located on the same substrate with a digital processor and signal processing circuits to read the outputs of the sensors. The bridge sensors are accessed by a switch network coupled to the plurality of bridge sensors to selectively provide an output from at least one of the plurality of bridge sensors. The switch network may be a multiplexer, which provides a periodically oscillating voltage to the sensors, to energize the sensors. The multiplexer may also provide output from the energized sensor to the digital processor.

Abstract: A system, computer program product and method of obtaining a performance parameter associated with a sensor, such as an accelerometer, is provided. The method includes applying an acceleration to the accelerometer and a first frequency to obtain a sensitivity of the accelerometer at the first frequency. A first self-test is performed on the accelerometer. The first self-test includes stimulating the accelerometer with a first self-test stimulation signal encoded with the first frequency, such that the accelerometer outputs a first signal. A self-test equivalent acceleration is then determined based, at least in part, on the first signal and the accelerometer sensitivity at the first frequency. A second self-test is performed on the accelerometer. The second self-test includes stimulating the accelerometer with a second self-test stimulation signal encoded with the second frequency, such that the accelerometer outputs a second signal.

Abstract: A reference point defined on a two dimensional or three dimensional orthogonal coordinate space and scale reference of respective axes are estimated based on a distribution on the three dimensional orthogonal coordinate space at the time when respective axial components of an acceleration data group comprised of plural acceleration data including multi-axial components and a importance group pertaining to the acceleration data group, and the respective acceleration data are corrected based on the estimated reference point and scale reference of the respective axes.

Abstract: A system and method are provided to calibrate a sheet velocity measurement derived from a drive nip system incorporating idler encoders. Testing has found that the velocity from an idler encoder system is subject to systematic errors, for example, errors that occur when the system is running media of different thicknesses. The system uses one or more nips with encoders mounted on the idlers and a number of point sensors that are spaced apart in the process direction. The point sensors are used to measure the transmit time of the sheet (lead edge or trail edge) between two sensor positions. The transit time is used to calculate the average sheet velocity. The average sheet velocity is compared with the velocity derived from the idler-encoders to derive a correction factor. The velocity sensor are used to calibrate the idler-encoder velocity sensors, providing a worthwhile improvement to idler-encoder technology for media handling (e.g., feeding, transport, and finishing) in direct marking systems.

Abstract: A method and apparatus for calibrating a gyro-sensor, by which a gyro-sensor can be calibrated using data which is obtained by measuring an angular velocity and a gyro output value of a moving body equipped with the gyro-sensor. The method includes measuring an angular velocity of a moving body and an average output value of the gyro-sensor when the moving body, equipped with the gyro-sensor, rotates, obtaining data about a characteristic equation of the gyro sensor using the measured angular velocity and the average output value and storing the data, and calibrating the gyro-sensor using the stored data about the characteristic equation.

Abstract: A method is disclosed in this invention for compensating a temperature dependent variation of an offset Voffset and sensitivity Vsensitivity parameters of an accelerometer. The method includes steps of a) Measuring a Sensitivity Vsensitivity(T0) and an Offset Voffset(T0) at a room temperature T0 to input to a microprocessor to calculate two tilt angles ?1 and ?2 in placing the accelerometer in a furnace for adjusting a controllable temperature therein; b) Keeping the accelerometer at the fixed tilt angle ?1 and adjusting the temperature of the furnace for measuring an output voltage at ?1 Vo(T, ?1) and keeping the accelerometer at another fixed tilt angle ?2 and adjusting the temperature of the furnace for measuring an output voltage at ?2 Vo(T, ?2); and c) solving equations to obtain the offset Voffset and sensitivity Vsensitivity parameters at different temperatures and storing these parameters in the microprocessor.

Abstract: A sensing circuit for a vibration type of angular rate sensor comprises a vibrator, driving unit, follow-up signal forming unit, normal voltage-range setting unit, and determining unit. The driving unit drives the vibrator to vibrate at a predetermined amplitude by using, as a feedback signal, an error voltage signal in which an amplitude of vibration of the vibrator is reflected. The follow-up signal forming unit forms, by using the error voltage signal, a follow-up signal following up the error voltage signal at changes which are gentler than changes in the error signal. The normal voltage-range setting unit sets a range of a normal voltage for the error voltage signal by using the follow-up signal. The determining unit determines whether or not the sensor circuit is in a malfunctioning condition, by using an estimation as to whether or not the error voltage signal is within the range of the normal voltage.

Abstract: A method for monitoring a rotation rate sensor comprising a vibration gyroscope that represents a band-pass filter and that is part of at least one control circuit, wherein the control circuit comprises a digital and analog components and excites the vibration gyroscope to vibrate with its natural frequency by supplying it with an excitation signal. An output signal can be gathered from the vibration gyroscope from which the excitation signal and the rotation rate signal can be derived by filtering and amplification. Redundant analog components and at least one analog to digital converter are used to measure analog signals and read characteristic values within the digital components and compare the measured characteristic values with limiting values.

Abstract: An innovative configuration of Miniaturized Smart Self-calibration EPD for mortar applications, as the azimuth/heading and elevation measurement device. This innovative EPD configuration uses only two FOGs or DTG and accelerometers and it is self-contained. This leads to a new EPD implementation that produces a small and light device with lower cost and adequate accuracy for the small dismounted mortar applications.

Abstract: To calibrate an accelerometer, a seismic cable that carries the accelerometer is rotated. Data measured by the accelerometer as the seismic cable is rotated is received, and at least one calibration parameter according to the received data is computed. The at least one calibration parameter is for use in calibrating the accelerometer.

Abstract: A laparoscopy simulator includes two rods and an orientation sensor that determines the orientation of the rods. An optical sensor is used to determine measurements of each rod based on the rotation of the rod around a central axis of the rod and a sliding of the rod along the central axis. An accelerometer is used to determine additional measurements of each rod based on a rotation of the rod around two additional rotation axes of the simulator. The measurements are used to determine the overall orientation of the rods.

Abstract: A method of calibrating once-around and harmonic errors of encoded nips is provided. An encoder with an index pulse is used to measure the velocity and rotation of the driven wheel or idler. The geometry of the drive train and wheel and idler is chosen so that their once around and harmonic frequencies are unique such that no other drive errors will generate these frequencies. The method includes running the idler or wheel at substantially constant velocity for N revolutions. Each index triggers the collection of velocity data, which is averaged for N revolutions. This process detects drive train motion errors that are periodic with respect to the timing of the index pulse (i.e., once per revolution of the wheel or idler). Once the velocity errors have been measured, corrections are made. This method may be incorporated in xerographic machines as part of a setup or calibration procedure.

Abstract: The present invention provides the stress detection method for force sensor device with multiple axis sensor device and force sensor device employing this method, whose installation angle is arbitrary. The stress detection method includes, first and second force sensors whose detection axes are orthogonal to each other. When the detection axis of first force sensor forms angle ? with direction of detected stress Ax, and the stress component of direction perpendicular to direction of the detected stress Ax is Az, output Apx of the axis direction of first force sensor is found as Apx=?x (Ax×cos ?+Az×sin ?), and output Apz of the axis direction of the second force sensor is found as Apz=?z (Ax×sin ?+Az×cos ?), and, when ?x and ?z are detection sensitivity coefficients of first and second force sensors respectively, the detection sensitivity coefficient ?z of second force sensor is set as ?z=?x tan ?, and the detected stress Ax is found as Ax=(Apx?Apz)/?x(cos ??tan ?×sin ?).

Abstract: A positioning and calibration system are provided for use in calibrating a single or multi axis sensitive instrument, such as an inclinometer. The positioning system includes a positioner that defines six planes of tangential contact. A mounting region within the six planes is adapted to have an inclinometer coupled thereto. The positioning system also includes means for defining first and second flat surfaces that are approximately perpendicular to one another with the first surface adapted to be oriented relative to a local or induced reference field of interest to the instrument being calibrated, such as a gravitational vector. The positioner is positioned such that one of its six planes tangentially rests on the first flat surface and another of its six planes tangentially contacts the second flat surface. A calibration system is formed when the positioning system is used with a data collector and processor.

Abstract: An oversampling electromechanical modulator, including a micro-electromechanical sensor which has a first sensing capacitance and a second sensing capacitance and supplies an analog quantity correlated to the first sensing capacitance and to the second sensing capacitance; a converter stage, which supplies a first numeric signal and a second numeric signal that are correlated to the analog quantity; and a first feedback control circuit for controlling the micro-electromechanical sensor, which supplies an electrical actuation quantity correlated to the second numeric signal.

Abstract: Systems, methods and circuits for implementing a self test in a slowly varying sensor. In one particular case, a circuit is provided that includes two filters operating in parallel. One of the filters is tailored for filtering normal operational signals, and operates at a first oversampling rate. The other filter is tailored for filtering test signals, and operates at a second oversampling rate. The second oversampling rate is generally less than the first oversampling rate. In various cases, the filter tailored for filtering normal operational signals may be programmed for operation across a plurality of oversampling rates.

Abstract: The present invention is directed to a calibration apparatus and method for calibrating and verifying the accuracy of a golf ball launch monitor. The apparatus includes a support structure and a rotatable wheel that has embedded golf balls evenly dispersed at a known distance from the center of the wheel, and a field of view opening in a protective cover. A power device, typically an electric motor, rotates the wheel at a predetermined speed to establish a known speed and spin rate of the golf balls. Each golf ball surface includes contrasting markings. Camera(s) of the launch monitor are focused on the field-of-view wherein each camera is triggered such that two images of a ball are captured. The monitor has a computer to analyze data for speed and spin rate of the golf balls. A comparison of this data to the established known speed and spin rate of the calibration apparatus enables determination of the accuracy and repeatability of the monitor.

Abstract: A system and method are provided to calibrate a sheet velocity measurement derived from a drive nip system incorporating idler encoders. Testing has found that the velocity from an idler encoder system is subject to systematic errors, for example, errors that occur when the system is running media of different thicknesses. The system uses one or more nips with encoders mounted on the idlers and a number of point sensors that are spaced apart in the process direction. The point sensors are used to measure the transmit time of the sheet (lead edge or trail edge) between two sensor positions. The transit time is used to calculate the average sheet velocity. The average sheet velocity is compared with the velocity derived from the idler encoders to derive a correction factor. The velocity sensor are used to calibrate the idler-encoder velocity sensors, providing a worthwhile improvement to idler-encoder technology for media handling (e.g., feeding, transport, and finishing) in direct marking systems.

Abstract: A system for correcting angular velocity measurements from a gyroscope and using the corrected angular velocity measurements to position an antenna used with a vehicle. The system determines an approximate null point voltage of a gyroscope of the type that produces a voltage related to an angular velocity to be measured by the gyroscope. The approximate null point is determined by sampling the output voltage to obtain a plurality of sampled voltages and choosing an approximate mode of the plurality of sampled voltages as the approximate null point voltage.

Abstract: In a travel angle detection system for a mobile object having a detector installed in the mobile object to produce angular velocity outputs successively, the detector outputs are read and one output is determined as a provisional calibration value indicative of zero-point. Integrated values of differences between the calibration value and successive outputs and output variation width are calculated. When they are within predetermined permissible ranges, the mobile object is determined to be in static condition and the calibration value is corrected by an average value of the integrated values. The travel angle of the mobile object is detected from the calibrated outputs of the detector, thereby achieving accurate calibration of detector output by enabling accurate determination of the static condition.

Abstract: A gyro sensor module built into a navigation system mounted into a mobile unit includes: a first gyro sensor detecting and outputting a first angular velocity ?1 around a first detection axis; a sign determination circuit for determining a sign of the first angular velocity ?1; a second gyro sensor detecting and outputting a second angular velocity ?2 around a second detection axis intersecting the first detection axis at an acute angle ?12; a sensor output correction circuit for correcting outputs of the first and second gyro sensors; and a computation circuit for computing ?? by equations ??=?(?1?2+SA2) and SA=(?2???1? cos ?12)/sin ?12 using a first angular velocity ?1? and a second angular velocity ?2? obtained by a correction performed by the sensor output correction circuit, and outputting an angular velocity ? obtained by multiplying the ?? by the sign of the first angular velocity ?? obtained by the sign determination circuit.